1. Field of the Invention
The present invention relates to a culture chamber used for the cultivation of cells or tissues of a human being or an animal. In particular, it relates to a culture chamber using a culture liquid, a culture apparatus using the culture chamber, and a liquid supplying method using the culture chamber.
2. Description of the Related Art
In the cultivation of cells or tissues of a human being or an animal, a culture liquid is used, and a vessel, such as a Petri dish, which houses the culture liquid and the cells or tissues, is used. By using them, a technology which makes the cells or tissues glow in the culture liquid within the vessel has been known. The culture liquid is a culture medium for the cells or tissues, and also performs a function as a transmission medium of nutrient and air such as oxygen. In the process of cultivation, nutrient, oxygen and so on are absorbed into the cells or tissues from the culture liquid. Because of this, in order to maintain the cells or tissues in a fresh condition by the supply of nutrient necessary for the cells or tissues, the removal of wastes, and so on, an exchange of the culture liquid is indispensable. For this exchange of the culture liquid, for example, a system which makes the culture liquid circulate from a source of the culture liquid to the vessel housing the cells or tissues through a circuit is used. In order to prevent the contamination of the culture liquid and a culture object due to unwanted bacteria, an airtight vessel and a closed system circuit are used in a system like this, for example.
In connection with such an exchange of a culture liquid and so on, there are a cell culture apparatus (The Japanese Laid Open Publication No. 2004-016194: a patent document 1) which performs the culture of cells while carrying out an exchange of a culture medium in a culturing container under a state separated from an outer environment, a cell and tissue culturing device (The Japanese Laid Open Publication No. 2003-061642: a patent document 2) which supplies a culture liquid to a chamber provided in a closed system circuit, a cell culture apparatus (The Japanese Laid Open Publication No. 2004-147555: a patent document 3) which makes a culture liquid and oxygen perfuse, and so on.
By the way, in the technology (the patent document 1) performing the exchange of a culture medium by sucking in cells, which are separated from an outer environment by a culture vessel, with a pipette nozzle and removing it to another culture vessel, or by injecting a new culture medium after sucking in a culture medium within a culture vessel to remove it, it is feared that unnecessary stress is applied to the cells under cultivation. Further, it is feared that the cells are lost due to the exchange of a culture medium, and so on. For example, as shown in FIG. 22, if a culture liquid 202 is injected to a culture object 204, which is housed in a Petri dish 200 together with the culture liquid 202, by a pipette nozzle 206, the culture liquid 202 which is injected makes a compressive force (a) and a shearing force (b) act on the culture object 204. Because of this, it is feared that these make stress against the culture object 204 and also make an outflow (c) of the cells from the culture object 204.
Further, in the cultivation (the patent document 2) using a closed system circuit, it is possible to perform the circulation of a culture liquid by the drive of a piston. However, it is feared that this circulation of the culture liquid gives excessive physical stimulation to a culture object, and that the physical stimulation changes it into cells or tissues having a character not able to forecast. For example, as shown in FIG. 23, in case in which a culture liquid 202 is injected into a culture chamber 208, which is provided in a closed circuit, through a tube path 210, a jet flow is generated in the vicinity of an entrance of the culture chamber 208, and the culture liquid 202 in the culture chamber 208 joins in the vicinity of its exit and increases its flow velocity. Because of this, it is feared that the cells and an extracellular matrix 212 receive a compressive force due to the jet flow in the vicinity of the entrance, and that the cells and an extracellular matrix 212 receive a high-speed flow to flow out in the vicinity of the exit. Further, it is also feared that, depending on stress given to the cells or tissues, these are changed into cells or tissues which have a character out of a purpose.
Like this, since the exchange of a culture liquid and the supply of a culture liquid dive an influence to cultivation, it is requested that the exchange and the supply are performed carefully, and that quick exchange processing is performed. However, in respect to problems like this, the patent documents 1 through 3 do not disclose anything. Further, these documents do not disclose or suggest a constitution which solves these problems.